Fill up with a lower-octane gasoline: Buy the lowest grade or octane of gasoline that is appropriate for your car. Unless your car requires premium gasoline, filling up your car with high-octane fuel is a waste of money. That pricey premium fuel won’t boost your car’s fuel economy or performance in the least, so skip it. If you’re not sure what grade of fuel works best for your car, open up your owner’s manual and take a look. As long as your engine doesn’t knock or ping when you fuel up with regular unleaded, you’re good to drive on this much cheaper gas. Passing on pricey premium gasoline could save you hundreds of dollars a year.
Pump up your tires. Don’t get caught driving on underinflated tires. Underinflated tires wear down more quickly and they also lower your car’s gas mileage.”Tires that have low pressure offer more resistance so the engine is going to work harder to keep the car at 60,” says Brian Moody, road test editor at Edmunds.com. Your car’s gas mileage may plummet by as much as 15 percent. Driving on underinflated tires may also reduce the life of your tires by 15 percent or more.
Use the right oil. You can improve your car’s gas mileage by 1 percent to 2 percent by using the manufacturer’s recommended grade of motor oil. Opt for motor oil with the words “energy conserving” on the API performance label. This oil contains friction-reducing additives.
Tighten up that gas cap. Gas will evaporate from your car’s gas tank if it has an escape. Loose, missing or damaged gas caps cause 147 million gallons of gas to evaporate each year, according to the Car Care Council. So be sure to tighten up that gas cap each time you fuel up your car.
Keep your engine in tune. Fixing a car that is out of tune or has failed an emissions test can boost gas mileage by about 4 percent. So be sure to give your car regular tune-ups. You’ll also want to watch out for worn spark plugs. A misfiring spark plug can reduce a car’s fuel efficiency by as much as 30 percent.